1. Field of the Invention
This invention relates generally to level and position indicating devices for use in construction, and more particularly to a level and position indicating device adapted for use in ceiling and roof construction.
2. Description of Related Art
The following art defines the present state of this field:
Dong, U.S. Pat. No. 5,864,956 describes a combination of square alloy rulers with precisely machined planes, each ruler unit having two 1.5v batteries and two bubble levels to level in all directions. A line generator is mounted in front of a laser diode module. This basic laser line ruler unit can produce an accurate laser level line or plumb line after it is calibrated. By adjusting the calibrating knob, the laser line ruler will produce a precise level line or plumb line when the level bubbles are centered. Putting a properly aligned level line unit and a properly aligned plumb line unit together will produce a cross line in front of the combination. Adding at least one more laser line ruler, that is combining three or more line units, will produce 90 degree lines, 45 degree lines, and 180 degree lines, as well as 270 degree lines up and down or on the right and left sides by simply adjusting the position of the relevant ruler. The housing of the ruler position of the relevant ruler. The housing of the ruler unit is machined with accurate planes and vertical angles. Therefore, the combination of several rulers can project accurate level lines, vertical lines, 45 degree lines, 90 degree lines, etc. This simple, small, and unique ruler combination is affordable to the public and can be widely used in hardwood layout and cutting, carpet cutting, squaring the surfaces of any plane object, etc. in addition to its usage in construction.
Ting, U.S. Pat. No. 5,842,282 describes a laser angle adjustment device for laser measuring instruments including a rectangular casing, a fixed bubble level and an adjustable bubble level mounted on the casing at right angles, a barrel turned in a hole in the casing, a top cover fixedly fastened to the barrel at one end to hold a laser module for providing a laser reference line for measurement.
Ohtomo et al., U.S. Pat. No. 5,819,424 describes an invention providing a laser leveling device, which comprises a light emitting unit for irradiating a laser beam, a rotating unit for rotating the laser beam for scanning, and a means for turning off the scanning laser beam so that a spot-like is formed in a specific direction. By forming a reference spot light, and aligning an irradiating point of the spot beam with the reference point, it is possible to install the laser leveling device to the reference point and to perform accurate positioning of the laser leveling device by the scanning line of the laser beam formed on a portion other than the spot.
Cupp, U.S. Pat. No. 5,604,987 describes a support for a laser beam generator in a carpenter""s level is positioned on the level so that the laser beam generated will lie in the plane of a flat reference surface of the level. A battery or other power supply is housed in the carpenter""s level together with circuitry to connect the power supply to the laser beam generator and preferably a switch allowing the generator to be turned off and on. Gauges may be employed in the level for vertical, as well as horizontal may be included. Such a gauge may be a commercial gauge such as an inclinometer. Preferably, however, a conventional gauge employing an arcuate tube filled with liquid having a bubble in it which seeks the highest level of the tube with calibration marks for accurately positioning the bubble. Such a gauge rotatably supported, but frictionally held in a selected position relative to the level enables a selected angle for the reference surface to repeatedly be used even without calibration. With calibration, it enables a selected angle relative to horizontal to be set from the calibrations so that the reference surface may be oriented at the set angle when using the level.
Breda, U.S. Pat. No. 5,566,459 describes a laser beam device that performs sightings and tracings which make use of a calibrated tube inside which resides a laser emitting component of which the optical emitting axis coincides with the mechanical axis of the tube, a mirror securely mounted at the end of the tube and set at a 45 degree angle from the incident laser beam, an end piece mounted and rotating on the end of the tube which includes a number of ports which can be brought to be coaxially centered in the reflected beam by simply rotating the end piece and a number of optical systems respectively mounted in the ports. The device provides flexibility without requiring additional set-up.
Huang, U.S. Pat. No. 5,495,675 describes a laser sight including a mounting base fixed to the bow back of a bow, a first holder frame fastened to the mounting base and adjusted in the X-axis direction, a second holder frame fastened to the first holder frame and adjusted in the Y-axis direction, a third holder frame fastened to the second holder frame and adjusted in the Z-axis direction and having a sight blade, and a laser module fastened to a swivel laser module holder on the third holder frame, wherein the swivel laser module holder is fastened to the third holder frame by an adjustment screw and can be turned about the adjustment screw to adjust the angle of inclination of the laser module for allowing the laser beam from the laser module to be aimed at a target when the sight blade is aligned with the target.
Rando et al., U.S. Pat. No. 5,459,932 describes an automatic plumb, level and pointing tool uses a visible laser diode to project light beams in two modes through two windows, In the first mode of operation, the unit is able to project a plumb-up beam and a level beam of light while resting on a surface which is as much as five degrees out of level. In the second mode of operation the unit is able to project two orthogonal beams of light both approximately in the horizontal plane for aligning one or more reference lines. An accurate, low cost method of generating level and plumb beams and planes of light is disclosed. One method uses an approximately leveled platform combined with a weak optical correction. The approximate leveling is done using a single wire or coil spring pendulum element which allows the platform to level itself to within a small fraction of true level, and remaining correction is provided by a weak negative lens or a weak reverse telescope. In alternative embodiments, all leveling is accomplished using a very flexible coil spring as a pendulum element, or a chain-link connection in combination with such a spring. Several accessories are disclosed for use with the laser tool.
Rando, U.S. Pat. No. 5,182,863 describes an automatic plumb, level, pointing and distance measuring tool uses a visible laser diode to project a beam in any of several different modes through a beam exit window. The tool, approximately the size and shape of a tape measure, can be placed on the edge to project a tilt-compensated vertical beam. Placed on another edge 90 degree rotated, the tool projects through the same exit window a tilt-compensated vertical beam. When laid on either of its larger flat sides, the tilt compensation becomes inoperative and the tool projects a beam, which is fixed relative to the housing. Acoustic distance measurement is facilitated using a second component or target side device, which is activated to send an acoustic signal across a space to be measured, toward the laser tool. A receiver in the laser tool detects arrival of the acoustic signal and causes the laser to project a characteristically modulated or pulsed beam, received at a photo-detector on the target side device. The acoustic transit time is clocked and distance is calculated and displayed. The use of a single acoustic transit time, without reflection increases distance-measuring range. Also, the visible laser beam projected between the two components provides a clear visual indication of the distance to be measured.
Genho, U.S. Pat. No. 3,897,637 describes a building level having a laser providing two and three beams simultaneously at 90 degrees to each other, and means for leveling and aligning the unit, and means for rotating the unit 90 degrees to provide grade and vertical.
The prior art teaches the construction and use of construction levels including those employing laser pointers. However, the prior art does not teach an apparatus that is enabled for mounting between the tee bars of a dropped ceiling so as to enable leveling of the ceiling and of a roof construction above the ceiling. The present invention fulfills these needs and provides further related advantages as described in the following summary.
The present invention teaches certain benefits in construction and use which give rise to the objectives described below.
The present invention provides a leveling and position indicating apparatus comprising an elongate frame with a pair of arms joined at a right angles, each of the arms terminating with an adjustable foot so that the device may be leveled, thereby establishing a level reference platform from which position and direction may be determined. A support bracket is adapted for rigid engagement with the elongate frame and is alternately positionable on it. A laser beam source is removably engagable with the support bracket for positioning a laser beam in a selected and measured direction relative to the reference platform. The feet are spaced for clamping onto the T-bar sections of a dropped ceiling so as to enable the placement of further T-bars, roof joists and other structural members at selected angles. The arms provide parallel, spaced apart grooves for mounting the apparatus onto the T-bars.
A primary objective of the present invention is to provide a leveling and position indicating apparatus having advantages not taught by the prior art.
Another objective is to provide such an apparatus enabled for clamping to a standard spacing between T-bars of a dropped ceiling so as to eliminate the need for using a plumb bob.
A further objective is to provide such an apparatus enabled for positioning a laser beam at a selected angle relative to a reference plane determined by the apparatus through adjustable feet.
A still further objective is to provide such an apparatus enabled for positioning the laser beam at any angle over a full circle.
A yet further objective is to provide such an apparatus enabled for being hooked over a joist, beam, or other fixed object when not in use, wherein a hook is provided at right angles for 90 degree mount to an adjacent surface and for preventing a fall from a ladder.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.